a glass window is to be fit in an aluminium frame . the temperature on the working day is 400C and the glass window measures exactly 20 cm X 30 cm . What should be the size of the aluminium frame so that there is no stress on the glass in winter even if the temperature drops to 00C. given that coefficients of linear expansion for glass and aluminium are 9 * 10-6 /0 C and 24 * 10-6 /0C respectively.
33Length and breadth of Al same and glass should be same at 00C..
Let it Be pxq
20=p(1+aΔθ) ....
30=q(1+aΔθ) .....
a = 9*10-6
Δθ=400
now let LxB be dimension of Al frame at 400
so L=p(1+bΔθ)
B=q(1+bΔθ)
b=24*10-6
we know value of p and q from above equations..
so LxB can be found...
